You would expect computer systems & APIs in the financial sector to be among the best maintained, documented, and supported.

The opposite is the case: APIs suddenly stop working as documented, without prior warnings, deprecating, or announcements. APIs will intermittently forget to include certain data columns. Authentication will kinda work twice a day, but only between 12pm and noon.

Once you caught up with all the breaking changes, they roll out a new release that breaks everything again.